Monday, June 16, 2014

The well-chewed calorie

Many of you have doubtless already seen the commentary in the New York Times by my friend and colleague, Dr. David Ludwig (with Mark Friedman, whom I don’t know), entitled: “Always Hungry? Here’s Why.” If you have not read the piece, I commend it to you.

Regarding Dr. Ludwig, he is indeed both colleague and friend, and I am proud to call him both. He is a prolific, insightful and accomplished researcher, and one of those rare individuals whose intellect sends out sparks to ignite better thinking by those around him. For whatever my opinion is worth, I consider Dr. Ludwig one of the best in the business of both learning what we need to know about diet and health, and putting it to good use.

Regarding the New York Timespiece, and the more scholarly commentary in JAMA on which it is based, I have a number of favorable impressions. The commentary essentially posits that we are not fat because we overeat, but overeat because we are fat, exploring the inner life of the adipocyte and its interactions with an array of hormones, insulin salient among them, to make that case. The commentary is thoughtful, well-reasoned and provocative. Dr. Ludwig’s excellent research, focused on glycemic index and load in particular, is cited for support.

But I am worried that even commentary of this caliber is subject to the law of unintended consequences, which has been the bane of public health nutrition for far too long already. In particular, I searched the text of both the pop culture and scholarly versions of this essay, and in neither case found any of these four words: survival, culture, satiety or synthesis. I think these are crucial considerations, and potentially grave omissions.

On Survival:Drs. Ludwig and Friedman posit that we overeat because we get fat, but that merely begs the question: Why did we get fat in the first place? They address this to some extent, but fail to emphasize what I think is the essential, and obvious answer: survival. Throughout most of human history, calories were relatively scarce and hard to get, and physical activity was unavoidable. We are adapted to that world. But we have devised a modern world in which physical activity is scarce and hard to get, and calories are unavoidable. Houston, we have a problem.

In a world of relative caloric scarcity and fairly constant demands for physical exertion, appetite for salt, sugar, fat, calories, variety, all fosters survival. In nature, you eat what you can when you can, and you don’t get fat not because you are trying to avoid it, but because survival is challenging and conspires against it. In an unnatural world of constant abundance of tasty calories and labor-saving technology, you behave as you always have, but wind up with very different results.

You get fat. And then, sure, being fat may propagate the problem in a number of ways, but the bedrock explanation for overeating is not being fat; that is an obvious chicken-and-egg conundrum. The bedrock explanation for getting fat is: we have made it fun (e.g., tasty food; sedentary recreation) and easy to get fat and hard (e.g., a need for constant restraint; hectic schedules; etc.) to avoid it.

On Culture:Culture is bigger than any one of us. Cultural variation in behavior and health outcomes tells us rather indelibly, whether we like the message or not, that the basic care and feeding of the human body is highly dependent on actions of the body politic.

Our inclination to keep chewing calories into ever smaller bits of academic grist may be the very opposite of what we really need: the big picture. Our culture marketsmulti-colored marshmallows to our kids, and tells them they are “part of a complete breakfast!” Highly paid advertising executives engineer the angle of gaze on cereal boxes by iconic cartoon characters to influence, maximally and subliminally, the responses of children and adults alike. And we need to ask why are we fat? Come on! Maybe “hypocrisy” should be on my list of missing key words, too. Our culture seems to have no shame of it.

On Satiety:Satiety refers to a feeling of fullness, and implies something about its duration as well. We have long recognized, all but intuitively, that the satiety attached to diverse foods is highly variable. For instance, we have referred in the vernacular to some foods as “stick to the ribs,” meaning they make, and keep us, full.

But now, again, welcome our cultural hypocrisy. We invite the likes of Dr. Ludwig to debate the origins of obesity, even as teams of Ph.D.’s work for Big Food companies to engineer foods that maximize the calories it takes to feel full. Michael Moss is only the most recent to tell us this tale; others have before. In a world where functional MRI scans and teams of scientists design foods so that bets that we “can’t eat just one” are entirely safe, the relevant question is not why so many of us are fat, but how on earth any of us manage not to be!

The key issue here is that inattention to satiety invites us to debate the relevance of calories, and carry on as if there is a choice to make between the laws of thermodynamics and the machinations of appetite. Why choose? The quantity of calories figures relevantly into energy balance and the hegemony of thermodynamics, while the quality and character of those calories determine how many it takes to feel full. The prevailing tendency in our culture is to maximize the calories it takes to feel full, making epidemic obesity little less than a fait accompli. We can reverse engineer this process to astonishingly good effect, but few in our society have the relevant skills.

On Synthesis:And finally, the dualistic view advanced here, calories must be about quantity, or quality; obesity must be cause, or effect, may obscure a truth that is both moreholistic, and more actionable. In other words, what we get in the commentary is another hypothesis, while in my opinion, what we most need is synthesis.

Consider, for instance, the work of another friend and colleague, and another exemplar of the academic method, Dr. Brian Wansink. Dr. Wansink’s research has shown that substantial variations in both the quantity and quality of foods consumed can be achieved by influencing such factors as lighting, placement and packaging, before ever even addressing the composition of the food itself. Instead of a seemingly endless parade of competing hypotheses about what truly matters, why not consider the possibility of a truth that is greater than the sum of its parts: Just about every aspect of modern culture that makes it modern is obesigenic, and if we want to fix the problem, we have to fix it comprehensively.

Calories count, but counting calories is tedious business. And besides, few people are willing to spend their lives hungry when they have the option of fullness and satisfaction. So the answer is to reduce the calories it takes to feel full. That means eating better food, which in turn requires knowing what “better” food is (we do); being able to find, choose and afford it (all possible, but how much better we could do!); combining better eating with routine physical activity; and shutting down the forces of cultural hypocrisy that invite us to wring our hands about epidemic obesity even while actively propagating it.

Drs. Ludwig and Friedman talk about the research we need. Maybe among it is a study of how a predilection for highlighting our doubts and debates as publicly as possible forestalls any meaningful action based on what we do know. Again, it would be as if your foot catches fire, and you feel compelled to read competing theories about combustion point, flammability, flame retardants, the partial pressure of atmospheric gases, wound care and skin grafting, before ever you fetch that pail of water. I say: Go for it!

We must, of course, parse and debate, explore and question to advance our understanding, which is far from complete, and farther still from perfect. But then again, how perfect does our knowledge of combustion need to be to fetch a pail of water if our foot catches fire? There is a point at which debating the subtleties of what we don’t know while failing to act on what we do know may come dangerously close to fiddling while Rome burns.

In other words, as good and erudite as Dr. Ludwig’s insights are, maybe the calorie has been sufficiently well chewed already. And maybe endless rumination paves the road to procrastination and ruin.

David L. Katz, MD, FACP, MPH, FACPM, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care. He is a board certified specialist in both Internal Medicine, and Preventive Medicine/Public Health, and Associate Professor (adjunct) in Public Health Practice at the Yale University School of Medicine. He is the Director and founder (1998) of Yale University's Prevention Research Center; Director and founder of the Integrative Medicine Center at Griffin Hospital (2000) in Derby, Conn.; founder and president of the non-profit Turn the Tide Foundation; and formerly the Director of Medical Studies in Public Health at the Yale School of Medicine for eight years. This post originally appeared on his blog at The Huffington Post.

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Members of the American College of
Physicians contribute posts from their own sites to
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Albert Fuchs,
MD
Albert Fuchs, MD, FACP, graduated from the
University of California, Los Angeles School of Medicine, where he
also did his internal medicine training. Certified by the American
Board of Internal Medicine, Dr. Fuchs spent three years as a
full-time faculty member at UCLA School of Medicine before opening
his private practice in Beverly Hills in 2000.

And Thus, It Begins
Amanda Xi, ACP Medical
Student Member, is a first-year medical student at the OUWB School
of Medicine, charter class of 2015, in Rochester, Mich., from which
she which chronicles her journey through medical training from day
1 of medical school.

Auscultation Ira S. Nash,
MD, FACP, is the senior vice president and executive director of the North Shore-LIJ
Medical Group, and a professor of Cardiology and Population Health at Hofstra North
Shore-LIJ School of Medicine. He is Board Certified in Internal Medicine and
Cardiovascular Diseases and was in the private practice of cardiology before joining the
full-time faculty of Massachusetts General Hospital.

Zackary Berger
Zackary Berger, MD, ACP Member, is a primary care doctor and
general internist in the Division of General Internal Medicine at
Johns Hopkins. His research interests include doctor-patient
communication, bioethics, and systematic reviews.

Controversies in Hospital
Infection Prevention
Run by three ACP
Fellows, this blog ponders vexing issues in infection prevention
and control, inside and outside the hospital. Daniel J Diekema, MD,
FACP, practices infectious diseases, clinical microbiology, and
hospital epidemiology in Iowa City, Iowa, splitting time between
seeing patients with infectious diseases, diagnosing infections in
the microbiology laboratory, and trying to prevent infections in
the hospital. Michael B. Edmond, MD, FACP, is a hospital
epidemiologist in Iowa City, IA, with a focus on understanding why
infections occur in the hospital and ways to prevent these
infections, and sees patients in the inpatient and outpatient
settings. Eli N. Perencevich, MD, ACP Member, is an infectious
disease physician and epidemiologist in Iowa City, Iowa, who
studies methods to halt the spread of resistant bacteria in our
hospitals (including novel ways to get everyone to wash their
hands).

Suneel Dhand, MD, ACP Member Suneel Dhand, MD,
ACP Member, is a practicing physician in Massachusetts. He has published numerous
articles in clinical medicine, covering a wide range of specialty areas including;
pulmonology, cardiology, endocrinology, hematology, and infectious disease. He has also
authored chapters in the prestigious "5-Minute Clinical Consult" medical textbook. His
other clinical interests include quality improvement, hospital safety, hospital
utilization, and the use of technology in health care.

Dr. Mintz' Blog
Matthew Mintz, MD, FACP, has practiced internal medicine for more
than a decade and is an Associate Professor of Medicine at an
academic medical center on the East Coast. His time is split
between teaching medical students and residents, and caring for
patients.

FutureDocs
Vineet Arora, MD, FACP, is Associate Program Director for the
Internal Medicine Residency and Assistant Dean of Scholarship &
Discovery at the Pritzker School of Medicine for the University of
Chicago. Her education and research focus is on resident duty
hours, patient handoffs, medical professionalism, and quality of
hospital care. She is also an academic hospitalist.

Glass Hospital
John H. Schumann, MD, FACP, provides transparency on the workings
of medical practice and the complexities of hospital care,
illuminates the emotional and cognitive aspects of caregiving and
decision-making from the perspective of an active primary care
physician, and offers behind-the-scenes portraits of hospital
sanctums and the people who inhabit them.

Gut Check
Ryan Madanick, MD, ACP Member, is a gastroenterologist at the
University of North Carolina School of Medicine, and the Program
Director for the GI & Hepatology Fellowship Program. He
specializes in diseases of the esophagus, with a strong interest in
the diagnosis and treatment of patients who have
difficult-to-manage esophageal problems such as refractory GERD,
heartburn, and chest pain.

David Katz, MD
David L. Katz, MD, MPH, FACP, is an internationally renowned
authority on nutrition, weight management, and the prevention of
chronic disease, and an internationally recognized leader in
integrative medicine and patient-centered care.

Just Oncology
Richard Just, MD, ACP Member, has 36 years in clinical practice of
hematology and medical oncology. His blog is a joint publication
with Gregg Masters, MPH.

Medical Lessons
Elaine Schattner, MD, FACP, shares her ideas on education, ethics
in medicine, health care news and culture. Her views on medicine
are informed by her past experiences in caring for patients, as a
researcher in cancer immunology, and as a patient who's had breast
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Mired in MedEd
Alexander M.
Djuricich, MD, FACP, is the Associate Dean for Continuing Medical
Education (CME), and a Program Director in Medicine-Pediatrics at
the Indiana University School of Medicine in Indianapolis, where he
blogs about medical education.

More Musings
Rob Lamberts, MD, ACP Member, a med-peds and general practice
internist, returns with "volume 2" of his personal musings about
medicine, life, armadillos and Sasquatch at More Musings (of a
Distractible Kind).

Prescriptions
David M. Sack, MD, FACP, practices general gastroenterology at a
small community hospital in Connecticut. His blog is a series of
musings on medicine, medical care, the health care system and
medical ethics, in no particular order.

The Blog of Paul Sufka
Paul Sufka,
MD, ACP Member, is a board certified rheumatologist in St. Paul,
Minn. He was a chief resident in internal medicine with the
University of Minnesota and then completed his fellowship training
in rheumatology in June 2011 at the University of Minnesota
Department of Rheumatology. His interests include the use of
technology in medicine.

Technology in (Medical)
Education
Neil Mehta, MBBS, MS, FACP, is interested in use of technology in
education, social media and networking, practice management and
evidence-based medicine tools, personal information and knowledge
management.

Peter A. Lipson,
MD
Peter A. Lipson, MD, ACP Member, is a practicing internist and
teaching physician in Southeast Michigan. The blog, which has been
around in various forms since 2007, offers musings on the
intersection of science, medicine, and culture.

Why is American Health Care So Expensive?
Janice
Boughton, MD, FACP, practiced internal medicine for 20 years before
adopting a career in hospital and primary care medicine as a locum
tenens physician. She lives in Idaho when not traveling.

World's Best Site
Daniel Ginsberg, MD,
FACP, is an internal medicine physician who has avidly applied
computers to medicine since 1986, when he first wrote medically
oriented computer programs. He is in practice in Tacoma,
Washington.

Other
blogs of note:

American Journal of
Medicine
Also known as the Green Journal, the American Journal of Medicine
publishes original clinical articles of interest to physicians in
internal medicine and its subspecialities, both in academia and
community-based practice.

Interact MD
Michael Benjamin, MD, ACP member, doesn't accept industry money so
he can create an independent, clinician-reviewed space on the
Internet for physicians to report and comment on the medical news
of the day.

PLoS Blog
The Public Library of Science's open access materials include a
blog.

White Coat
Rants
One of the most popular anonymous blogs written by an emergency
room physician.

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